Get Grid Column Name

Hi all,

I have problem getting the column name from grid. what i want to achieve is if user click one of value on the grid it will display the details. In order to filter which details display to the users, i need the column name that user click. I already set the grid and column name and i tried using this api_component.getclickgridcolumnname, but it return nothing.

all i need is how to tell which column was user click, so i can display the correct details ( each column on the grid will display different details ).

and here are my script ( the v_id always returns null value) :

PROCEDURE SHOW_LIST_DETAIL IS

  v_gridName            varchar2(1000); 
  v_datasourceName      varchar2(1000);
  v_pqcode              varchar2(30);
  v_prcode              varchar2(30);
  v_row                 API_DATASOURCE.TT_ROW;
  v_columns             API_DATASOURCE.TT_COLUMNS;
  v_columnName          varchar2(255);
  v_id varchar2(200);
 BEGIN
  v_gridName        := API_APPLICATION.GETFOCUSEDCOMPONENT;
  v_datasourceName  := API_COMPONENT.GETDATASOURCE(v_gridName);       
  v_row             := API_DATASOURCE.GETROW(v_datasourceName);       
  v_columns         := API_DATASOURCE.GETCOLUMNNAMES(v_datasourceName);        
  ---
  API_APPLICATION.SHOWPOPUPMESSAGE('Grid ' || v_gridName);
  v_id := API_COMPONENT.GETCLICKEDGRIDCOLUMNNAME(v_gridName);
  API_APPLICATION.SHOWPOPUPMESSAGE('Test' || v_id);

END;